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181.
Nicolás M. Suárez Ana González Eva Betancor José J. Pestano 《Conservation Genetics》2009,10(3):581-583
The blue chaffinch, Fringilla teydea, is an endemic species of the Canary Islands. This species is formed by two subspecies: The Teneriffean blue chaffinch (F. t. teydea), and the endangered Gran Canarian blue chaffinch, (F. t. polatzeki). Here we report the isolation and characterization of nine tetranucleotide microsatellites (AAAG and AAAT) from the Gran
Canarian subspecies, using an enrichment protocol. An average of 7.8 alleles per locus and an average observed heterozygosity
of 0.773 were found (n = 28). The loci were tested for their ability to cross amplify in the Teneriffean subspecies and in the common chaffinch
(Fringilla coelebs). These microsatellites will be used to manage a captive breeding programme for the endangered Gran Canarian subspecies. 相似文献
182.
Marcia Ricci 《Biodiversity and Conservation》2006,15(10):3111-3130
Was realized field studies and ex situ propagation on the vascular flora of Juan Fernández Archipelago during 15 year period.
To evaluate the conservation status of a total of 133 species and subspecies of vascular endemic plants I used a IUCN classification
founding: 2 species extinct, 1 extinct in it natural habitat, 52 critically endangered, 37 endangered and 9 vulnerable. Thus,
73.8% are contained in a threat category; only 24 taxon can be considered to be of a lesser conservation concern. The largest
threat of extinction is a reduction in individuals in local populations resulting in small, isolated populations. This habitat
fragmentation and a reduction in endemic flora has also impacted endemic fauna. Besides, during this period was propagated
in nurseries a total of 80 of these species and subspecies (60%). It seem clear the necessity to continue to actions conserve
this particular ecosystem. 相似文献
183.
Coexistence of recently diverged and ecologically similar sister species in complete sympatry represents a particularly compelling case for sympatric speciation. This study investigates the possible sympatric origin of two coexisting bark beetle taxa that utilize the same host plant on the island of La Palma in the Canary Islands. Aphanarthrum subglabrum and Aphanarthrum glabrum ssp. nudum breed inside dead twigs of Euphorbia lamarckii plants and are closely related to the allopatric A. glabrum ssp. glabrum in Tenerife, El Hierro and La Gomera. We tested the various speciation hypotheses in a genealogical context, using mitochondrial gene fragments from Cytochrome Oxidase I and 16S, and nuclear gene fragments from Enolase, Elongation Factor 1alpha and Histone H3. Phylogenetic analyses of the combined nuclear DNA data strongly supported a sister relationship between two sympatric and reproductively isolated taxa in La Palma. However, network analyses of subdivided nonrecombinant segments of the Enolase locus indicated a closer relationship between the two allopatric A. glabrum subspecies, suggesting multiple colonizations of this island. A bimodal distribution of mtDNA haplotypes in La Palma further documented the independent colonization of this island, with asymmetric introgression of mtDNA between two lineages. Consequently, the sympatric origin of the La Palma species is concluded to have involved allopatric phases before the parallel colonization of this island and subsequent introgression at some loci. The clear genetic and morphological evidence for reproductive isolation between these species suggests that the sympatric completion of divergence was either due to initial genetic incompatibility, morphological character displacement in male genitalia, or a combination of these factors. 相似文献
184.
Navascués M Vaxevanidou Z González-Martínez SC Climent J Gil L Emerson BC 《Molecular ecology》2006,15(10):2691-2698
Chloroplast microsatellites are becoming increasingly popular markers for population genetic studies in plants, but there has been little focus on their potential for demographic inference. In this work the utility of chloroplast microsatellites for the study of population expansions was explored. First, we investigated the power of mismatch distribution analysis and the F(S) test with coalescent simulations of different demographic scenarios. We then applied these methods to empirical data obtained for the Canary Island pine (Pinus canariensis). The results of the simulations showed that chloroplast microsatellites are sensitive to sudden population growth. The power of the F(S) test and accuracy of demographic parameter estimates, such as the time of expansion, were reduced proportionally to the level of homoplasy within the data. The analysis of Canary Island pine chloroplast microsatellite data indicated population expansions for almost all sample localities. Demographic expansions at the island level can be explained by the colonization of the archipelago by the pine, while population expansions of different ages in different localities within an island could be the result of local extinctions and recolonization dynamics. Comparable mitochondrial DNA sequence data from a parasite of P. canariensis, the weevil Brachyderes rugatus, supports this scenario, suggesting a key role for volcanism in the evolution of pine forest communities in the Canary Islands. 相似文献
185.
Monte Garroutte Falk Huettmann Campbell O. Webb Stefanie M. Ickert-Bond 《植物分类学报:英文版》2018,56(5):476-497
This is the first comprehensive analysis of vascular plant diversity patterns in the Aleutian Islands to identify and quantify the impact of Aleutian Island distance dispersal barriers, geographical, ecological and anthropogenic factors. Data from public Open Access databases, printed floristic accounts, and from collections made by the primary author were used to develop an Aleutian floristic database. The most common plant distribution pattern was “an eastern origin community”, though it compared similarly to the “Western” and “Widespread” distribution pattern. We established an ecological plant community composition class for each island, based on clustering species assemblage dissimilarity measurements (Jaccard Index), and a measurement of phylogenetic dissimilarity (UniFrac). We modelled these composition classes and species richness values in non‐parametric algorithmic models and concepts (data cloning using machine learning, stochastic boosting‐ TreeNet) based on classic and Aleutians‐specific island biogeography hypotheses. Plant species richness is strongly associated with the equilibrium model variables of area and island isolation, as well as distance to the Alaska Peninsula, and island total stream length. Species composition is strongly associated with the landmass groups during the last glacial maximum, maximum island elevation, island isolation and island area. Phylogenetic composition is associated with island area, distance from the islands to the Chukotka Peninsula, maximum island elevation, island geologic age, and island isolation. This study extends the equilibrium theory of island biogeography by including additional drivers of diversity during the Anthropocene, such as the landmass during the LGM, as well as factors that may be related to anthropogenic extinction rate. 相似文献
186.
Ferrous iron‐ and ammonium‐rich diffuse vents support habitat‐specific communities in a shallow hydrothermal field off the Basiluzzo Islet (Aeolian Volcanic Archipelago).
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187.
188.
Crouch NR Smith GF 《Botanical journal of the Linnean Society. Linnean Society of London》2011,166(3):301-309
South Africa, as a megadiverse country (±21 700 vascular plants, 4800 vertebrates and 68 900 invertebrates described), is presently engaged with an extended, modified Global Strategy for Plant Conservation (GSPC). The country is fortunate in having a strong tradition of systematics research and, inter alia, houses several million preserved plant specimens (±1 million databased and georeferenced), allowing taxonomists and conservationists to track both the occurrence and distribution of indigenous and naturalized plant species. These rich local resources have been extensively drawn upon to deliver, with varying degrees of success, the 16 outcome-oriented GSPC 2010 Targets. The National Environmental Management: Biodiversity Act (NEMBA, 2004), the National Biodiversity Strategy and Action Plan (NBSAP) and the National Biodiversity Framework (NBF) have provided a robust legislative, enabling and policy framework for making operational and advancing GSPC-related efforts. However, within an emerging economy, the conservation of biodiversity has competed for government resources with housing, sanitation, primary education, basic health care and crime prevention, delivery of which translates to the currency of politicians: votes. A key challenge identified by local (and global) biodiversity scientists for the current GSPC phase is broad-scale advocacy, communicating the changing state of nature, and the inter-relatedness of biodiversity and human well-being. The nature of meeting this challenge is explored. 相似文献
189.
In the course of a survey on plant diseases and their pathogenic fungi in the Nansei Islands, some noteworthy fungi were collected. Among them, four fungi newly found in Japan were described with some mycological and pathological notes. These species are Septoria gardeniae Savelli, causing circular leaf spot of Gardenia; Phyllosticta cordylinophila Young apud Stevens, causing brown leaf spot of Cordyline; Phyllosticta drummondii Vanef et van der Aa, causing brown needle blight of Araucaria; and Phyllachora minuta Hennings, causing tar spot of Hibiscus. 相似文献
190.
This study records the chromosome numbers of 10 species ofStreptocarpus; nine of the counts are new. With the exception ofS. buchananii of mainland Africa, all the results are for plants endemic to Madagascar and the Comoro Islands. While there is a strong correlation between basic number and growth form in the two subgenera of the genus on the African mainland (x = 15 among caulescent species in subgenusStreptocarpella; x = 16 among acaulescent species in subgenusStreptocarpus), the situation appears more complex among Madagascan and Comoro Island species. One notable example of deviation from this correlation is shown byS. papangae, a shrubby caulescent species, with 2n = 32 (x = 16). Polyploidy in the genus appears to be absent on mainland Africa, but is present in Madagascar and the Comoro Islands, ranging from tetraploidy to octoploidy. Evolutionary implications of the cytological observations are considered. 相似文献